Mobile electronic devices are becoming more and more prevalent, with providers offering customers more and more features. Such features include the transmission of digital video data, such as video mail, movies, television shows, video games; the transmission of digital audio data, such as music, soundtracks for digital video, etc., and the like. A prior standard for the transmission of digital video data, known as DVB-T (established by the European Telecommunication Standards Institute, or ETSI), had been established for the general transmission of video data in a digital network, but that standard had its drawbacks when applied in a mobile device. In particular, the DVB-T standard placed a greater power drain on the mobile device, shortening its battery life.
The reason for this power drain lies in the multiplexing of the data in the DVB-T standard. In that standard, data for multiple different elementary services (ES) were closely multiplexed together, thereby requiring receiving mobile devices to have their receiving circuitry turned on continuously during use. This continuous use of the circuitry drained battery power.
To address this, the ETSI has since developed a new standard, known as DVB-H, that overcomes this drawback by using time slicing. The concept of time slicing is to send an elementary stream in bursts using significantly higher bitrate compared to the average bitrate of the elementary stream or the bitrate required if the elementary stream was transmitted using conventional bandwidth management of DVB-T. The burst is a set of sections containing parts of an elementary stream. Between the bursts, data of the elementary stream is not transmitted, allowing other elementary streams to use the bandwidth otherwise allocated. This enables the receiver to stay active for a fragment of the time, while receiving bursts of a requested service. As noted in section 9.2.3 of the European Standard ETSI EN 301 192, in an example, if the amount of data to be transmitted in a burst is 2 Mbits, and the total allocated bandwidth during a burst is 15 Mbps (over related transport packets), the maximum duration of the burst is 140 ms (from the beginning of the first transport packet, to the end of the last one). If the elementary stream carries one streaming service at constant bandwidth of 350 kbps, the average time between bursts is about 6.10 s.
The use of such time slices for the transmission of real-time data suffers from a problem that plagues all wireless transmission systems—the loss of data through signal interference or other network error. Various error correction and concealment schemes have been used to try and compensate for this lost data. For example, the DVB-H standard employs forward error control (FEC) methods, which seek to address the lost data by transmission of repair data calculated according to particular error correcting code schemes. However, existing methods are not perfect, and there is a need for improved methods of minimizing the effects of lost data.